1. Field of the Invention
The present invention relates to a colored radiation-sensitive composition which is suitable as a color resist used for forming color pixels, a colored cured film and a color filter which use the colored radiation-sensitive composition, a production method thereof, and a solid-state image sensor and an image display device which include the color filter.
2. Description of the Related Art
In recent years, as a digital camera, a camera-equipped cellular phone, and the like have come into wide use, and a demand for a solid-state image sensor such as a CCD image sensor has greatly increased. As a key device of these displays or optical devices, a color filter is used, and it is increasingly required for the color filter to have a higher degree of sensitivity and to be miniaturized. Generally, the color filter has colored patterns of three primary colors including red (R), green (G), and blue (B) and plays a role of separating transmitted light into the three primary colors.
Colorants used for the color filter are commonly required to have the following properties. That is, it is required for the colorants to have light absorptivity preferable for color reproducibility, not to have optical disorders such as uneven optical density that results in light scattering, color unevenness, or rough texture, to exhibit excellent toughness, for example, heat resistance, light fastness, or the like, during the production thereof or under the condition in which the colorants are used, to have great molar absorptivity, and to be able to be formed into a thin film.
One of the examples of methods for producing the color filter includes a pigment dispersion method. The method for producing a color filter by using the pigment dispersion method by means of a photolithography or an inkjet method is stable with respect to light or heat since this method uses a pigment. However, the pigment is in the form of fine particles, and as a result, problems such as light scattering, color unevenness, and rough texture arise in some cases. In order to solve the problems, micronization of the pigment is performed. However, there is a problem in that it is difficult for the micronized pigment to have dispersion stability.
Examples of the method for producing the color filter that can replace the pigment dispersion method include a method of using a dye as a coloring material. In a composition, a dye is present in a dissolved state, and accordingly, light scattering, color unevenness, or rough texture caused by a pigment can be inhibited. The heat resistance or light fastness of a dye is poorer than that of a pigment. Therefore, in recent years, for the purpose of improving toughness, preventing migration of the color of dye to other layers, and the like, attempts at ameliorating dyes have been made (for example, see JP2011-95732A and JP2000-162429A).